In this project, we propose to develop and test a communication strategy to support clinical decision making about a key step in a personalized breast cancer screening paradigm, the age of initiating breast cancer screening. The absolute benefit of mammography screening varies according to risk of developing breast cancer, a risk that depends upon multiple factors and particularly age. Women at lower risk of breast cancer will experience smaller absolute benefits from screening, but are likely to have the same risk of false positives and other adverse effects. This variation in the risk-benefit ratio of a particular screening strategy according to individual characteristics is fundamental to the personalized screening paradigm. However, there is little evidence about how best to communicate this information to women considering screening. The proposed project includes two phases. In Phase 1, we will conduct a series of experimental studies to examine the effect of alternative communication strategies on comprehension and the correlation between screening intentions and the absolute benefit and risk in the scenarios. Based on recent advances in communication theory and our preliminary work, we will focus on the potential impact of exemplars and of information addressing the expertise and motives of the information sources. In Phase 2, we will test a decision aid based upon the results of Phase 1 in an cross-over, clustered randomized controlled trial in a primary care population, examining its effects on knowledge, decision satisfaction and screening.focusing on the correlation between the absolute benefit of screening and screening utilization.